I find Dreamweaver CC very unstable on my system running the latest Yosemite, particularly when working multiple remote sites simultaneously.
If I have files open from several different sites and toggle between them to change, save and upload, Dreamweaver will hang for up to 8 full minutes on the beach ball. Now, I know you must be wondering why wait for 8 minutes on the beach ball instead of just Force Quitting? Well, I found that force quitting makes it even buggier upon reopening and ends up taking more time.
It's very frustrating... my workflow has been GREATLY slowed down switching from CS5 to CC. I'm a very sad customer because no amount of pref & plist ditching solves it.
Mac Pro 4,1 w/ 16GB RAM.